Nanoemulsion based on sugar fatty esters or on sugar fatty ethers and its uses in the cosmetics, dermatological and/or ophthalmological fields

ABSTRACT

A nanoemulsion, the oily globules of which have a number-average size of less than 100 nm, comprising a surfactant which is solid at a temperature of less than or equal to 45° C., which surfactant is chosen from esters of a fatty acid and of a sugar and ethers of a fatty alcohol and of a sugar, and at least one oil having a molecular weight of greater than 400, the ratio by weight of the amount of oily phase to the amount of surfactant ranging from 2 to 10. The nanoemulsion may be used for cosmetics and dermatological applications, in particular for moisturizing the skin and/or mucous membranes, as well as for treating the hair, and in the ophthalmological field, as an eye lotion for treating the eyes.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a nanoemulsion based on asurfactant which is solid at a temperature of less than or equal to 45°C., which surfactant is chosen from esters of a fatty acid and of asugar and ethers of a fatty alcohol and of a sugar, and on at least oneoil having a molecular weight of greater than 400, the ratio by weightof the amount of oily phase to the amount of surfactant ranging from 2to 10.

[0003] The invention also relates to a process for the preparation ofthe said nanoemulsion and to its uses in the cosmetics, dermatologicaland/or ophthalmological fields. This nanoemulsion is stable on storageand can comprise large amounts of oil while retaining good transparencyand while having good cosmetic properties.

[0004] 2. Description of the Background

[0005] Nanoemulsions are oil-in-water emulsions, the oil globules ofwhich have a very fine particle size, that is to say a number-averagesize of less than 100 nm. They are generally manufactured by mechanicalfragmentation of an oily phase in an aqueous phase in the presence of asurfactant. In the case of nanoemulsions, the very small size of theoily globules is obtained in particular by virtue of at least one passthrough a high-pressure homogenizer. The small size of the globulesconfers on them cosmetically advantageous properties which distinguishthem from conventional emulsions: they are transparent and exhibit anovel texture. They can also carry active agents more efficiently.

[0006] Transparent microemulsions are known in the state of the art. Incontrast to nanoemulsions, microemulsions are not, strictly speaking,emulsions; they are transparent solutions of micelles swollen by oil,which oil is generally a very-short-chain oil (e.g. hexane or decane)and is solubilized by virtue of the joint presence of a significantamount of surfactants and of cosurfactants which form the micelles. Thesize of the swollen micelles is very small owing to the small amount ofoil which they can solubilize. This very small size of the micelles isthe cause of their transparency, as with nanoemulsions. However, incontrast to nanoemulsions, microemulsions are spontaneously formed bymixing the constituents, without contributing mechanical energy otherthan simple magnetic stirring. The major disadvantages of microemulsionsare related to their high proportion of surfactants, leading tointolerance and resulting in a sticky feel during application to theskin. Furthermore, their formulation range is generally very narrow andtheir temperature stability very limited.

[0007] In addition, nanoemulsions are known in the state of the artcomprising an amphiphilic lipid phase composed of phospholipids, waterand oil. These emulsions exhibit the disadvantage of being unstable onstorage at conventional storage temperatures, namely between 0 and 45°C. They lead to yellow compositions and produce rancid smells whichdevelop after several days of storage.

[0008] Nanoemulsions stabilized by a lamellar liquid crystal coating,obtained by the combination of a hydrophilic surfactant and of alipophilic surfactant, are also known. However, these combinations areproblematic to prepare. Furthermore, the nanoemulsions obtained exhibita waxy and film-forming feel which is not very pleasant for the user.

[0009] Furthermore, the document EP-A-728,460 discloses nanoemulsionsbased on fluid non-ionic amphiphilic lipids. However, thesenanoemulsions exhibit the disadvantage of having a sticky effect duringapplication to the skin.

[0010] The need therefore remains for nanoemulsions which have neitherthe disadvantages of those of the prior art nor the disadvantages ofmicroemulsions.

SUMMARY OF THE INVENTION

[0011] The present inventors have now discovered, unexpectedly, that theuse of a surfactant which is solid at a temperature of less than orequal to 45° C., which surfactant is chosen from sugar esters or ethers,and of at least one oil having a molecular weight of greater than 400(that is to say, 400 grams per mole) makes it possible to obtain novelnanoemulsions exhibiting all the advantages of known nanoemulsionswithout their disadvantages.

[0012] Accordingly, the present invention relates to a nanoemulsion,comprising:

[0013] an oily phase dispersed in an aqueous phase and having oilglobules with a number-average size of less than 100 nm,

[0014] a surfactant which is solid at a temperature of less than orequal to 45° C., wherein the surfactant is selected from the groupconsisting of esters of a fatty acid and of a sugar and ethers of afatty alcohol and of a sugar, and

[0015] at least one oil having a molecular weight of greater than 400,

[0016] where the ratio by weight of the amount of oily phase to theamount of surfactant is 2 to 10.

[0017] The present invention also provides a method of caring for,treating and/or making up the skin, face and/or scalp, comprisingapplying the nanoemulsion to the skin, face and/or scalp.

[0018] The present invention also provides a method of caring for and/ortreating the hair, comprising applying the nanoemulsion to the hair.

[0019] The present invention also provides a method of caring for and/ormoisturizing the skin, mucous membranes and/or scalp, comprisingapplying the nanoemulsion to the skin, mucous membranes and/or scalp.

[0020] The present invention also provides a method of preparing thenanoemulsion.

[0021] A more complete appreciation of the invention and many of theattendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription.

DETAILED DESCRIPTION OF THE INVENTION

[0022] The nanoemulsions according to the invention generally have atransparent to bluish appearance. Their transparency is measured by atransmittance coefficient at 600 nm ranging from 10 to 90% or else by aturbidity ranging from 60 to 600 NTU and preferably from 70 to 300 NTU,which turbidity is measured with a Hach Model 2100 P portableturbidimeter. This range for the transparency includes all specificvalues and subranges therebetween, such as 20%, 30%, 50%, 75% and 85%.This range for the turbidity includes all specific values and subrangestherebetween, such as 80, 90, 125, 150, 200 and 250 NTU.

[0023] The oil globules of the nanoemulsions of the invention have anumber-average size of less than 100 nm and preferably ranging from 20to 75 nm and more preferably from 40 to 60 nm. This range includes allspecific values and subranges therebetween, such as 25, 30, 50, 80 nm.The decrease in the size of the globules makes it possible to promotethe penetration of the active principles into the surface layers of theskin (carrier effect).

[0024] The surfactant which is solid at a temperature of less than orequal to 45° C. which can be used in the nanoemulsion of the inventionis chosen exclusively from esters of a fatty acid and of a sugar, ethersof a fatty alcohol and of a sugar, and their mixtures, which means thatthe nanoemulsion of the invention is devoid of any surfactant other thansugar fatty esters or fatty ethers.

[0025] The esters of a fatty acid and of a sugar which can be used assurfactants in the nanoemulsions according to the invention are solid ata temperature of less than or equal to 45° C. and can be chosen inparticular from the group consisting of esters or mixtures of esters ofa C₈-C₂₂ fatty acid and of sucrose, maltose, glucose or fructose andesters or mixtures of esters of a C₁₄-C₂₂ fatty acid and ofmethylglucose.

[0026] The C₈-C₂₂ or C₁₄-C₂₂ fatty acids which form the fatty unit ofthe esters which can used in the nanoemulsion of the invention comprisea saturated or unsaturated linear alkyl chain respectively comprisingfrom 8 to 22 or from 14 to 22 carbon atoms. The fatty unit of the esterscan be chosen in particular from stearates, behenates, arachidonates,palmitates, myristates, laurates, caprates and their mixtures. Stearatesare preferably used.

[0027] Mention may be made, by way of examples of esters or of mixturesof esters of a fatty acid and of sucrose, maltose, glucose or fructose,of sucrose monostearate, sucrose distearate, sucrose tristearate andtheir mixtures, such as the products sold by Croda under the nameCrodesta F50, F70, F110 and F160, respectively having an HLB(Hydrophilic Lipophilic Balance) of 5, 7, 11 and 16; and, by way ofexamples of esters or of mixtures of esters of a fatty acid and ofmethylglucose, of the distearate of methylglucose and of polyglycerol-3sold by Goldschmidt under the name of Tego-care 450. Mention may also bemade of glucose or maltose monoesters, such as methylO-hexadecanoyl-6-D-glucoside and methyl O-hexadecanoyl-6-D-maltoside.

[0028] The ethers of a fatty alcohol and of a sugar which can be used assurfactants in the nanoemulsion according to the invention are solid ata temperature of less than or equal to 45° C. and can be chosen inparticular from the group consisting of ethers or mixtures of ethers ofa C₈-C₂₂ fatty alcohol and of glucose, maltose, sucrose or fructose andethers or mixtures of ethers of a C₁₄-C₂₂ fatty alcohol and ofmethylglucose. They are in particular alkyl polyglucosides.

[0029] The C₈-C₂₂ or C₁₄-C₂₂ fatty alcohols which form the fatty unit ofthe ethers which can be used in the nanoemulsion of the inventioncomprise a saturated or unsaturated linear alkyl chain respectivelycomprising from 8 to 22 or from 14 to 22 carbon atoms. The fatty unit ofthe ethers can in particular be chosen from the decyl, cetyl, behenyl,arachidyl, stearyl, palmityl, myristyl, lauryl, capryl or hexadecanoylunits and their mixtures, such as cetearyl.

[0030] Mention may be made, by way of examples of ethers of a fattyalcohol and of a sugar, of alkyl polyglucosides, such as decyl glucosideand lauryl glucoside, sold, for example, by Henkel under the respectivenames Plantaren 2000 and Plantaren 1200, cetostearyl glucoside,optionally as a mixture with cetostearyl alcohol, sold, for example,under the name Montanov 68 by Seppic, under the name Tego-care CG90 byGoldschmidt and under the name Emulgade KE 3302 by Henkel, and arachidylglucoside, for example in the form of the mixture of arachidyl andbehenyl alcohols and of arachidyl glucoside sold under the name Montanov202 by Seppic.

[0031] According to a specific embodiment of the invention, use is moreparticularly made, as surfactant, of sucrose monostearate, sucrosedistearate, sucrose tristearate and their mixtures, the distearate ofmethylglucose and of polyglycerol-3, and alkyl polyglucosides.

[0032] Depending on whether its character is more hydrophilic or morelipophilic, the surfactant can be introduced into the aqueous phase orinto the oily phase of the nanoemulsion.

[0033] The amount of surfactant in the nanoemulsion of the invention canrange, for example, from 0.2 to 15% by weight and preferably from 1 to8% by weight with respect to the total weight of the nanoemulsion. Theseranges include all specific values and subranges therebetween, such as0.5, 1, 2, 5, 8, 10 and 12% by weight.

[0034] The ratio by weight of the amount of the oily phase to the amountof surfactant ranges from 2 to 10 and preferably from 3 to 6. This rangeincludes all specific values and subranges therebetween, such as 4,5,and 8. The term “amount of oily phase” is understood here to mean thetotal amount of the constituents of this phase without including theamount of surfactant.

[0035] The nanoemulsion according to the invention comprises at leastone oil with a molecular weight of greater than 400. The oils with amolecular weight of greater than 400 can be chosen from oils of animalor vegetable origin, mineral oils, synthetic oils and silicone oils, andtheir mixtures. Mention may be made, as oils of this type, of, forexample, isocetyl palmitate, isocetyl stearate, avocado oil or jojobaoil.

[0036] In addition, the oily phase can optionally comprise other oilsand in particular oils having a molecular weight of less than 400. Theseoils are also chosen from oils of animal or vegetable origin, mineraloils, synthetic oils and silicone oils. Mention may be made, forexample, as oils with a molecular weight of less than 400, ofisododecane, isohexadecane, volatile silicone oils, isopropyl myristate,isopropyl palmitate or C₁₁-C₁₃ isoparaffin.

[0037] The oily phase can also comprise fatty substances other than theoils indicated above, such as fatty alcohols, for example stearyl, cetyland behenyl alcohols, fatty acids, for example stearic, palmitic andbehenic acids, oils of fluorinated type, waxes, gums and their mixtures.

[0038] The nanoemulsions in accordance with the invention comprise anamount of oily phase preferably ranging from 2 to 40% and better stillfrom 5 to 30% by weight with respect to the total weight of thenanoemulsion, the proportion of oil(s) having a molecular weight ofgreater than 400 preferably representing at least 40% by weight of theoily phase. These ranges for the amount of oily phase include allspecific values and subranges therebetween, such as 8, 10, 12, 15, 20,25 and 35% by weight.

[0039] According to a specific embodiment of the invention, thenanoemulsion of the invention additionally comprises one or more ionicamphiphilic lipids.

[0040] The ionic amphiphilic lipids which can be used in thenanoemulsions of the invention are preferably chosen from the groupformed by anionic amphiphilic lipids, cationic amphiphilic lipids andalkylsulfonic derivatives.

[0041] The anionic amphiphilic lipids can be more particularly chosenfrom the group formed by:

[0042] the alkaline salts of dicetyl and dimyristyl phosphate;

[0043] the alkaline salts of cholesterol sulphate;

[0044] the alkaline salts of cholesterol phosphate;

[0045] lipoamino acids and their salts, such as mono- and disodiumacylglutamates, such as the disodium salt of N-stearoyl-L-glutamic acidsold under the name Acylglutamate HS21 by Ajinomoto;

[0046]  the sodium salts of phosphatidic acid;

[0047]  phospholipids.

[0048] The alkylsulfonic derivatives can more particularly be chosenfrom the alkylsulfonic derivatives of formula (I):

[0049] in which R represents an alkyl radical comprising from 16 to 22carbon atoms, in particular the C₁₆H₃₃ and C₁₈H₃₇ radicals, taken as amixture or separately, and M is an alkali metal, such as sodium.

[0050] The cationic amphiphilic lipids can more particularly be chosenfrom the group formed by quaternary ammonium salts, fatty amines andtheir salts.

[0051] The quaternary ammonium salts are, for example:

[0052] those which exhibit the following general formula (II):

[0053] in which the R₁ to R₄ radicals, which can be identical ordifferent, represent a linear or branched aliphatic radical comprisingfrom 1 to 30 carbon atoms or an aromatic radical, such as aryl oralkylaryl. The aliphatic radicals can comprise heteroatoms, such as, inparticular, oxygen, nitrogen, sulphur or halogens. The aliphaticradicals are, for example, chosen from alkyl, alkoxy,polyoxy(C₂-C₆)alkylene, alkylamido, (C₁₂-C₂₂)alkylamido(C₂-C₆)alkyl,(C₁₂-C₂₂)alkyl acetate or hydroxyalkyl radicals comprising approximatelyfrom 1 to 30 carbon atoms; X is an anion chosen from the group of thehalides, phosphates, acetates, lactates, (C₂-C₆)alkyl sulphates, oralkyl- or alkylarylsulphonates. Preference is given, as quaternaryammonium salts of formula (II), to, on the one hand, tetraalkylammoniumchlorides, such as, for example, dialkyldimethylammonium oralkyltrimethylammonium chlorides in which the alkyl radical comprisesapproximately from 12 to 22 carbon atoms, in particularbehenyltrimethylammonium, distearyldimethylammonium,cetyltrimethylammonium and benzyldimethylstearylammonium chlorides, oralternatively, on the other hand, stearamidopropyldimethyl(myristylacetate)ammonium chloride, sold under the name “Ceraphyl 70” by Van Dyk.

[0054] imidazolinium quaternary ammonium salts, such as, for example,those of following formula (III):

[0055] in which R₅ represents an alkenyl or alkyl radical comprisingfrom 8 to 30 carbon atoms, for example derived from tallow fatty acids;R represents a hydrogen atom, an alkyl radical comprising from 1 to 4carbon atoms or an alkenyl or alkyl radical comprising from 8 to 30carbon atoms; R₇ represents an alkyl radical comprising from 1 to 4carbon atoms; R₈ represents a hydrogen atom or an alkyl radicalcomprising from 1 to 4 carbon atoms; and X is an anion chosen from thegroup of the halides, phosphates, acetates, lactates, alkyl sulphates,or alkyl- or alkylarylsulphonates. R₅ and R₆ preferably denote a mixtureof alkenyl or alkyl radicals comprising from 12 to 21 carbon atoms, forexample derived from tallow fatty acids, R₇ preferably denotes a methylradical and R₈ preferably denotes hydrogen. Such a product is, forexample, sold under the name “Rewoquat W 75” by Rewo.

[0056] quaternary diammonium salts of formula (IV):

[0057] in which R₉ denotes an aliphatic radical comprising approximatelyfrom 16 to 30 carbon atoms; R₁₀, R₁₁, R₁₂, R₁₃ and R₁₄ are chosen fromhydrogen or an alkyl radical comprising from 1 to 4 carbon atoms; and Xis an anion chosen from the group of the halides, acetates, phosphates,nitrates and methyl sulphates.

[0058] Such quaternary diammonium salts comprise in particularpropanetallowdiammonium dichloride.

[0059] According to a preferred embodiment of the invention, a lipoaminoacid is used as ionic amphiphilic lipid.

[0060] The ionic amphiphilic lipids can be introduced into one or otherphase of the nanoemulsion. When they are present in the nanoemulsion ofthe invention, they can be used in concentrations preferably rangingfrom 0.01 to 5% by weight and more particularly from 0.25 to 1% byweight with respect to the total weight of the nanoemulsion.

[0061] The emulsions in accordance with the present invention cancomprise additives for improving the transparency of the formulation.

[0062] These additives are preferably chosen from the group formed by:

[0063] lower alcohols comprising from 1 to 8 carbon atoms and moreparticularly from 2 to 6 carbon atoms, such as ethanol;

[0064] glycols, such as glycerol, propylene glycol, 1,3-butylene glycol,dipropylene glycol, pentylene glycol, isoprene glycol and polyethyleneglycols comprising from 4 to 16 and preferably from 8 to 12 ethyleneoxide units;

[0065] sugars, such as glucose, fructose, maltose, lactose or sucrose.

[0066] These additives can be used as a mixture. When they are presentin the nanoemulsion of the invention, they can be used at concentrationspreferably ranging from 0.01 to 30% by weight with respect to the totalweight of the nanoemulsion and better still from 5 to 20% by weight withrespect to the total weight of the nanoemulsion. This range includes allspecific values and subranges therebetween, such as 0.02, 0.05, 0.5, 1,2, 10, 15 and 25% by weight. The amount of alcohol(s) and/or of sugar(s)preferably ranges from 5 to 20% by weight with respect to the totalweight of the nanoemulsion and the amount of glycol(s) preferably rangesfrom 5 to 15% by weight with respect to the total weight of thenanoemulsion.

[0067] In addition, the use of the alcohols as defined above atconcentrations greater than or equal to 15% by weight makes it possibleto obtain preservative-free emulsions.

[0068] The nanoemulsions defined above can constitute compositions fortopical use and in particular cosmetic or dermatological compositions.They can also be used as ophthalmic vehicles.

[0069] Also included in the scope of the invention is, therefore, acomposition for topical use, characterized in that it is composed of ananoemulsion as defined above. A composition for topical use comprises aphysiologically acceptable medium, that is to say compatible with theskin, mucous membranes, scalp, eyes and/or hair.

[0070] Another aspect of the invention is an ophthalmic vehicle,characterized in that it is composed of a nanoemulsion as defined above.

[0071] The nanoemulsions of the invention can comprise water-soluble orfat-soluble active principles having a cosmetic, dermatological orophthalmic activity. The fat-soluble active principles are in the oilyglobules of the emulsion, whereas the water-soluble active principlesare in the aqueous phase of the emulsion. Mention may be made, by way ofexamples of active principles, of vitamins, such as vitamin E, and theirderivatives and in particular their esters, provitamins, such aspanthenol, humectants and sun-screen agents.

[0072] Mention may be made, as ophthalmic active principles, of, forexample, antiglaucoma agents, such as betaxolol; antibiotics, such asacyclovir; antiallergics; anti-inflammatory agents, such as ibuprofenand its salts, diclofenac and its salts, or indomethacin; or antiviralagents.

[0073] The nanoemulsions in accordance with the invention can beprovided in the form of a lotion, serum, cream, milk or toilet water andcan comprise adjuvants commonly used in the cosmetics, dermatologicaland ophthalmic fields, such as, for example, gelling agents,preservatives, antioxidants and fragrances. They can also be provided inthe form of an eye lotion, in particular for ophthalmologicalapplications.

[0074] Mention may be made, among the gelling agents which can be used,of cellulose derivatives, algal derivatives, natural gums and syntheticpolymers, such as polymers and copolymers of carboxyvinyl acids, forexample those sold under the name Carbopol by Goodrich.

[0075] Another subject-matter of the invention is a process for thepreparation of a nanoemulsion as defined above, this process comprisingthe mixing of the aqueous phase and the oily phase with vigorousstirring at a temperature ranging from 10 to 80° C. and then ahomogenization of the mixture at a pressure preferably ranging from6×10⁷ Pa to 18×10⁷ Pa (high-pressure homogenization). The shearingpreferably ranges from 2×10⁶ s⁻¹ to 5×10⁸ s⁻¹ and better still from1×10⁸ s⁻¹ to 3×10⁸ s⁻¹ (s⁻¹ signifies second⁻¹).

[0076] The nanoemulsion of the invention can be used, for example, forcaring for, treating or making up the skin, face and/or scalp.

[0077] Another subject-matter of the invention is therefore the cosmeticuse of the nanoemulsion as defined above for caring for, treating and/ormaking up the skin, face and/or scalp.

[0078] In addition, the nanoemulsion of the invention can also be usedfor caring for and/or treating the hair. It makes it possible to obtaina deposit of oil on the hair, which renders the latter glossier and moreresistant to styling, without, however, making it lank. It also makes itpossible, as a pretreatment, to improve the effects of dyeing orpermanent waving.

[0079] Another subject-matter of the invention is therefore the cosmeticuse of the nanoemulsion as defined above for caring for and/or treatingthe hair.

[0080] The nanoemulsion according to the invention makes possible inparticular good moisturizing of the skin, mucous membranes and/or scalpand is particularly suited to the treatment of dry skin.

[0081] Another subject-matter of the invention is therefore a cosmeticprocess for caring for and/or moisturizing the skin, mucous membranesand/or scalp, characterized in that a nanoemulsion as defined above isapplied to the skin, mucous membranes and/or scalp.

[0082] The invention also relates to the use of the nanoemulsionaccording to the invention in the manufacture of a dermatologicalcomposition intended for the treatment of dry skin.

[0083] Regarding the uses described above, one skilled in the art willrecognize that the compositions of the inventions are to be appliedusing amounts and techniques customary for the dermatological andcosmetic fields.

[0084] Finally, the invention also relates to the use of thenanoemulsion according to the invention in the manufacture of anophthalmological composition.

EXAMPLES

[0085] Having generally described this invention, a furtherunderstanding can be obtained by reference to certain specific exampleswhich are provided herein for purposes of illustration only and are notintended to be limiting unless otherwise specified. The amounts shownare as % by weight.

Example 1 Fluid Make-Up Remover Oily Phase

[0086] Tego-Care 450 (Company Goldschmidt) 4.5% Disodium salt ofN-stearoyl-L-glutamic acid (Acylglutamate HS21 0.5% from Ajinomoto)Isocetyl stearate (M.W. = 508)  10% Isopropyl myristate (M.W. = 270)  5%

Aqueous Phase

[0087] Glycerol 5% Dipropylene glycol 10% Water 65%

[0088] A transparent nanoemulsion is obtained, the size of the globulesof which is 49 nm and the turbidity of which is 218 NTU.

Example 2 Make-Up Removing Gel Oily Phase

[0089] Crodesta F50 (Company Croda) 4.5% Disodium salt ofN-stearoyl-L-glutamic acid (Acylglutamate HS21 0.5% from the companyAjinomoto) Isocetyl stearate (M.W. = 508)  20% C₁₁-C₁₃ Isoparaffin (M.W.= 170) 2.5% Isohexadecane (M.W. = 226) 2.5%

Aqueous Phase

[0090] Glycerol 5% Dipropylene glycol 10% Water 55%

[0091] A gelled transparent nanoemulsion is obtained, the size of theglobules of which is 45 nm and the turbidity of which is 260 NTU.

Example 3 Scented Water Oily Phase

[0092] Crodesta F70 (Company Croda) 4.5%   Disodium salt ofN-stearoyl-L-glutamic acid (Acylglutamate 0.5%   HS21) (CompanyAjinomoto) Soybean oil (M.W. of the order of 900) 6% Volatile siliconeoil (M.W. = 106) 2% Fragrance 3% Vitamin E acetate 0.5%   Ethanol 10% 

Aqueous Phase

[0093] Glycerol   5% Water 68.5%

[0094] A transparent nanoemulsion is obtained, the size of the globulesof which is 39 nm and the turbidity of which is 96 NTU.

Example 4 Fluid Make-Up Remover Oily Phase

[0095] Tego-Care CG90 (Company Goldschmidt) 4.5% Disodium salt ofN-stearoyl-L-glutamic acid (Acylglutamate HS21 0.5% from the companyAjinomoto) Isocetyl stearate (M.W. = 508)  10% Isopropyl myristate (M.W.= 270)   5%

Aqueous Phase

[0096] Glycerol 5% Dipropylene glycol 10% Water 65%

[0097] A transparent nanoemulsion is obtained, the size of the globulesof which is 43 nm and the turbidity of which is 145 NTU.

Example 5 Care Gel Oily Phase

[0098] Montanov 68 (Company Seppic) 4.5%   Disodium salt ofN-stearoyl-L-glutamic acid (Acylglutamate 0.5%   HS21 from the companyAjinomoto) Soybean oil (M.W. of the order of 900) 9% Avocado oil (M.W.of the order of 900) 9% Volatile silicone oil (M.W. = 106) 6%

Aqueous Phase

[0099] Glycerol 5% Dipropylene glycol 10% Water 56%

[0100] A gelled transparent nanoemulsion is obtained, the size of theglobules of which is 46 nm and the turbidity of which is 240 NTU.

[0101] Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

[0102] This application is based on French Patent Application Serial No.98-15765, filed on Dec. 14, 1998, and incorporated herein by referencein its entirety.

1. A nanoemulsion, comprising: an oily phase dispersed in an aqueousphase and having oil globules with a number-average size of less than100 nm, a surfactant which is solid at a temperature of less than orequal to 45° C., wherein the surfactant is selected from the groupconsisting of esters of a fatty acid and of a sugar and ethers of afatty alcohol and of a sugar, and at least one oil having a molecularweight of greater than 400, wherein the ratio by weight of the amount ofoily phase to the amount of surfactant is 2 to
 10. 2. The nanoemulsionaccording to claim 1, having a turbidity of 60 to 600 NTU.
 3. Thenanoemulsion of claim 1, wherein the amount of surfactant is 0.2 to 15%by weight with respect to the total weight of the nanoemulsion.
 4. Thenanoemulsion of claim 1, wherein the ratio by weight of the amount ofoily phase to the amount of surfactant is 3 to
 6. 5. The nanoemulsion ofclaim 1, wherein the oil globules have an average size of 20 to 75 nm.6. The nanoemulsion of claim 1, wherein the surfactant is selected fromthe group consisting of esters or mixtures of esters of a C₈-C₂₂ fattyacid and of sucrose, maltose, glucose or fructose, esters or mixtures ofesters of a C₁₄-C₂₂ fatty acid and of methylglucose, ethers or mixturesof ethers of a C₈-C₂₂ fatty alcohol and of glucose, maltose, sucrose orfructose, and ethers or mixtures of ethers of a C₁₄-C₂₂ fatty alcoholand of methylglucose.
 7. The nanoemulsion of claim 1, wherein thesurfactant is selected from the group consisting of sucrosemonostearate, sucrose distearate, sucrose tristearate and theirmixtures, the distearate of methylglucose and of polyglycerol-3, andalkyl polyglucosides.
 8. The nanoemulsion of claim 1, wherein the oilwith a molecular weight of greater than 400 is selected from the groupconsisting of oils of animal or vegetable origin, mineral oils,synthetic oils and silicone oils, and mixtures thereof.
 9. Thenanoemulsion of claim 1, wherein the oily phase additionally comprisesat least one oil having a molecular weight of less than
 400. 10. Thenanoemulsion of claim 1, wherein the oily phase comprises at least 40%by weight of oil(s) having a molecular weight of greater than 400 withrespect to the total weight of the oily phase.
 11. The nanoemulsion ofclaim 1, wherein the amount of oily phase is 2 to 40% by weight withrespect to the total weight of the nanoemulsion
 12. The nanoemulsion ofclaim 1, further comprising at least one ionic amphiphilic lipidselected from the group consisting of anionic amphiphilic lipids,cationic amphiphilic lipids and alkylsulfonic derivatives.
 13. Thenanoemulsion according to claim 12, wherein the ionic amphiphilic lipidsare selected from the group consisting of the alkaline salts of dicetyland dimyristyl phosphate; the alkaline salts of cholesterol sulphate;the alkaline salts of cholesterol phosphate; the salts of lipoaminoacids; the sodium salts of phosphatidic acid; phospholipids; thealkylsulfonic derivatives of formula (I):

in which R represents C₁₆-C₂₂ alkyl radicals, taken as a mixture orseparately, and M is an alkali metal; quaternary ammonium salts, fattyamines and their salts; and mixtures thereof.
 14. The nanoemulsion ofclaim 12, wherein the amount of ionic amphiphilic lipid(s) is 0.01 to 5%by weight with respect to the total weight of the nanoemulsion.
 15. Thenanoemulsion of claim 1, further comprising an additive which improvesthe transparency thereof and selected from the group consisting loweralcohols, glycols, sugars and mixtures thereof.
 16. The nanoemulsion ofclaim 15, wherein the additive is present in a concentration rangingfrom 5 to 20% by weight with respect to the total weight of thenanoemulsion.
 17. The nanoemulsion of claim 1, further comprising acosmetic, dermatological or ophthalmological active agent.
 18. Acomposition suitable for topical use comprising the nanoemulsion ofclaim
 1. 19. An ophthalmic vehicle comprising the nanoemulsion ofclaim
 1. 20. A method of caring for, treating and/or making up the skin,face and/or scalp, comprising applying the nanoemulsion of claim 1 tothe skin, face and/or scalp.
 21. A method of caring for and/or treatingthe hair, comprising applying the nanoemulsion of claim 1 to the hair.22. A method of caring for and/or moisturizing the skin, mucousmembranes and/or scalp, comprising applying the nanoemulsion of claim 1to the skin, mucous membranes and/or scalp.
 23. A method of preparingthe nanoemulsion of claim 1, comprising: mixing the aqueous phase andthe oily phase with vigorous stirring at an ambient temperature rangingfrom 10 to 80° C. and then homogenizing the mixture at a pressureranging from 6×10⁷ Pa to 18×10⁷ Pa.
 24. The process of claim 23, whereinsaid mixing is conducted at a shearing of 2×10⁶ s⁻¹ to 5×10⁸ s⁻¹.